You can have dd show the progress of a write by specifying “status=progress” in the command line arguments.
sudo dd if=Downloads/CentOS-8-x86_64-1905-boot.iso of=/dev/sdb status=progress
Example:
bob@localhost:~$ sudo dd if=Downloads/CentOS-8-x86_64-1905-boot.iso of=/dev/sdb status=progress 559690240 bytes (560 MB, 534 MiB) copied, 96 s, 5.8 MB/s <-- This is shown while writing. 1093632+0 records in 1093632+0 records out 559939584 bytes (560 MB, 534 MiB) copied, 96.0339 s, 5.8 MB/s